Papers by PROF. VENKATAYOGI SUDARSHAN
AccordingtotheWorldHealthOrganizationrecommendation,the
optimal fluoride concentrationlevelsindr... more AccordingtotheWorldHealthOrganizationrecommendation,the
optimal fluoride concentrationlevelsindrinkingwaterhavetobe
in therangeof0.5and1.5mg/Lsincethispermissiblerangeis
essential fornormalmineralizationofbonesandteethaswellas
for dentalenamelformationinhuman'sbody Bell andbudwig,
1970;AdimallaandVenkatayogi,2017;NarsimhaandSudarshan,
2013,2016;2017[1,2,4,5,6]. Ifcontinuesintakeofhigh fluoride
(41.5)watercanseverelycausedentalandskeletal fluorosis. The
investigatedareapeoplemajorlydependongroundwaterfor
drinking purposesand fluoride concentrationrangedfrom0.2to
7.4mg/Lwithmeanconcentrationof2.7mg/Landdatawas
compared withWHOguidelinesfordrinkingpurposes.Overall,
data revealsthatthe57%ofgroundwatersamplesdatawasnot
safe fordrinkingpurposes.Therefore,distributionof fluoride inthe
groundwaterofMedakregioninTelanganawassuggestedto
intake drinkingwater,whicharebelowlevelof fluoride con-
centration inthegroundwaterandtakecareabouthealthimpli-
cations.
Geochemical investigations on 20 groundwater samples, collected from borewells located on the ban... more Geochemical investigations on 20 groundwater samples, collected from borewells located on the banks of Musi river, has been carried out for pH, EC, Ca 2+ , Mg 2+ , K + , Na + , SO 4 2-, Cl -, CO 3 2-, HCO 3 -, NO 3 -, TH and TDS. The results revealed that concentration of most of the ions exceed the prescribed permissible limits making the water unsuitable for drinking purpose. The results have been utilized for the characterization of groundwater based on USDA, Wilcox and Piper classification methods.
Fifty groundwater samples were collected during pre and post monsoon seasons in 2002 to study the... more Fifty groundwater samples were collected during pre and post monsoon seasons in 2002 to study the hydrogeochemistry of major ions in the different geological formations of Macherla and Piduguralla area of Guntur district, Andhra Pradesh, India. Analysis was carried out for pH, electrical conductivity (EC), total dissolved solids (TDS), total hardness (TH), calcium (Ca 2+), magnesium (Mg 2+), sodium (Na +), potassium (K +), carbonate (CO 3 2-), bicarbonate (HCO 3-), chloride (Cl-), sulphate (SO 4 2-), nitrate (NO 3-) and fluoride (FIt It is observed that nearly 50% of the groundwater is composed of more than 45 mg/L of nitrate and more than 1 mg/L of fluoride. EC of 32% of groundwater is more than the permissible limits. TDS is more than 500 mg/L in the groundwater of entire area.
Biogeochemical investigations of plant species Oriza sativa has been carried out in the Patancher... more Biogeochemical investigations of plant species Oriza sativa has been carried out in the Patancheru industrial area of Medak district, Andhra Pradesh to study the distribution of major, trace and Rare Earth Elements in the root and leaves of the plant species. The results and distribution patterns are discussed. It is observed that most of the toxic trace elements and major oxides are accumulated in high concentration in edible plant species Oryza sativa.
Applied Water Science , 2017
The major objective of this study was to locate
the vulnerable areas in terms of fluoride contami... more The major objective of this study was to locate
the vulnerable areas in terms of fluoride contamination. A
total of 34 groundwater samples were collected from major
drinking water sources in rural areas of Basara, Telangana,
and studied with reference to the distribution and hydrogeochemistry
of fluoride. The geochemical trend of
groundwater in the study area demonstrates that sodium is
the dominant cation (Na?[Ca2?[Mg2?[K?) and
chloride is the dominant anion (Cl–[HCO3
–[
SO4
2–[CO3
2–[NO3
–[F–). The fluoride concentration
varied from 0.06 to 4.33 (1.13 ± 0.90) mg L-1 with the
highest fluoride level at Karegaon village (4.33 mg L-1).
Seven locations showed the presence of fluoride in excess
of permissible levels.
Groundwater is a significant resource in India for domestic, irrigation and industrial needs. Hyd... more Groundwater is a significant resource in India for domestic, irrigation and industrial needs. Hydrogeochemical investigations were carried out in selected villages of south-western parts of Adilabad district, where groundwater is the main source of drinking water. The study area is occupied by pink and grey granites of Archaean age. 34 groundwater samples were collected from hand/bore pumps and analyzed for pH, Electrical Conductivity (EC), Total Dissolved Solids (TDS), Total Hardness (TH), Calcium (Ca 2+), Magnesium (Mg 2+), Sodium (Na +), Potassium (K +), Carbonate (CO 3 2-), Bicarbonate (HCO 3 -), Chloride (Cl -), Sulphate (SO 4 2-), Nitrate (NO 3 -) and Fluoride (F
Assessment of suitability of groundwater for domestic and agricultural purposes was carried out i... more Assessment of suitability of groundwater for domestic and agricultural purposes was carried out in Chityal area, Nalgonda district of Andhra Pradesh. Groundwater is the major source for domestic and agricultural activity in the study area. 70% of the F -in groundwater samples is within the potable limit of 1.5 mg/L. Suitability of groundwater for irrigation purpose was evaluated based on US Salinity diagram, which shows that 80% of the total groundwater falls in the zone of high-salinity hazard (C3) and low-sodium hazard (S1) type. The Wilcox diagram shows that most of the groundwater (70%) falls in the category of good to permissible for irrigation purposes. The residual sodium carbonate (RSC) in groundwater is less than 1.25 meq/L and hence, suitable for irrigation. Residual sodium bicarbonate concentration varied from -1.39 to 0.86 meq/L in the study area. All the samples collected from study area are found to be satisfactory (<5 meq/L) for irrigation purposes. Introduction Gr...
Applied Water Science , 2017
Hydrogeochemical investigation has been carried out in the granitic terrain of Siddipet area, Med... more Hydrogeochemical investigation has been carried out in the granitic terrain of Siddipet area, Medak district, Telangana State, India with an aim to understand the distribution of fluoride in the groundwater and to understand the relationship of fluoride with other major ions, and also to identify the high fluoride-bearing groundwater zones. 104 groundwater samples were analyzed in the study area for fluoride and other major ions like calcium, magnesium, chloride, carbonate, bicarbonate, sodium, potassium, sulfate, and nitrate in addition to pH and electrical conductivity. The studies revealed that the concentration of fluoride in groundwater is ranging from 0.2 to 2.2 mg L-1 with a mean of 1.1 mg L-1. Nearly 22 % of groundwater has more than the permissible limit of fluoride (1.5 mg L-1), which is responsible for the endemic dental fluorosis in the area concerned. Geo-chemical classification of groundwater shows that Na– HCO 3 , Ca–Cl, and Ca–HCO 3 –Na are the dominant hydrochemical facies. Gibbs diagram shows rock–water interaction dominance and evaporation dominance, which are responsible for the change in the quality of water in the hard rock aquifer of the study area. The groundwater in villages and its environs are affected by fluoride contamination , and consequently majority of the population living in these villages suffer from dental fluorosis. Hence, they are advised to consume drinking water which has less than 1.5 mg L-1 fluoride to avoid further fluorosis risks.
Groundwater is a significant resource in India for domestic, irrigation and industrial needs. Hyd... more Groundwater is a significant resource in India for domestic, irrigation and industrial needs. Hydrogeochemical investigations were carried out in selected villages of south-western parts of Adilabad district, where groundwater is the main source of drinking water. The study area is occupied by pink and grey granites of Archaean age. 34 groundwater samples were collected from hand/bore pumps and analyzed for pH, Electrical Conductivity (EC), Total Dissolved Solids (TDS), Total Hardness (TH), Calcium (Ca 2+), Magnesium (Mg 2+), Sodium (Na +), Potassium (K +), Carbonate (CO 3 2-), Bicarbonate (HCO 3 -), Chloride (Cl -), Sulphate (SO 4 2-), Nitrate (NO 3 -) and Fluoride (F
Geoscience Frontiers, 2014
The Deccan Syneclise is considered to have significant hydrocarbon potential. However, significan... more The Deccan Syneclise is considered to have significant hydrocarbon potential. However, significant hydrocarbon discoveries, particularly for Mesozoic sequences, have not been established through conventional exploration due to the thick basalt cover over Mesozoic sedimentary rocks. In this study, near-surface geochemical data are used to understand the petroleum system and also investigate type of source for hydrocarbons generation of the study area. Soil samples were collected from favorable areas identified by integrated geophysical studies. The compositional and isotopic signatures of adsorbed gaseous hydrocarbons (methane through butane) were used as surface indicators of petroleum micro-seepages. An analysis of 75 near-surface soil-gas samples was carried out for light hydrocarbons (C 1 eC 4 ) and their carbon isotopes from the western part of Tapti graben, Deccan Syneclise, India. The geochemical results reveal sites or clusters of sites containing anomalously high concentrations of light hydrocarbon gases. High concentrations of adsorbed thermogenic methane (C 1 ¼ 518 ppb) and ethane plus higher hydrocarbons (SC 2þ ¼ 977 ppb) were observed. Statistical analysis shows that samples from 13% of the samples contain anomalously high concentrations of light hydrocarbons in the soil-gas constituents. This seepage suggests largest magnitude of soil gas anomalies might be generated/source from Mesozoic sedimentary rocks, beneath Deccan Traps. The carbon isotopic composition of methane, ethane and propane ranges are from À22.5& to À30.2& PDB, À18.0& to 27.1& PDB and 16.9&e32.1& PDB respectively, which are in thermogenic source. Surface soil sample represents the intersection of a migration conduit from the deep subsurface to the surface connected to sub-trappean Mesozoic sedimentary rocks. Prominent hydrocarbon concentrations were associated with dykes, lineaments and presented on thinner basaltic cover in the study area, which probably acts as channel for the micro-seepage of hydrocarbons.
Frontiers of Earth Science, 2014
ABSTRACT Microbial prospecting of hydrocarbons is based on the detection of anomalous population ... more ABSTRACT Microbial prospecting of hydrocarbons is based on the detection of anomalous population of hydrocarbon oxidizing bacteria in the surface soils, indicates the presence of subsurface oil and gas accumulation. The technique is based on the seepage of light hydrocarbon gases such as C1–C4 from the oil and gas pools to the shallow surface that provide the suitable conditions for the development of highly specialized bacterial population. These bacteria utilize hydrocarbon gases as their only food source and are found enriched in the near surface soils above the hydrocarbon bearing structures. The methodology involves the collection of soil samples from the survey area, packing, preservation and storage of samples in pre-sterilized sample bags under aseptic and cold conditions till analysis and isolation and enumeration of hydrocarbon utilizing bacteria such as methane, ethane, propane, and butane oxidizers. The contour maps for the population density of hydrocarbon oxidizing bacteria are drawn and the data can be integrated with geological, geochemical, geophysical methods to evaluate the hydrocarbon prospect of an area and to prioritize the drilling locations thereby reducing the drilling risks and achieve higher success in petroleum exploration. Microbial Prospecting for Oil and Gas (MPOG) method success rate has been reported to be 90%. The paper presents details of microbial prospecting for oil and gas studies, excellent methodology, future development trends, scope, results of study area, case studies and advantages.
Assessment of suitability of groundwater for domestic and agricultural purposes was carried out i... more Assessment of suitability of groundwater for domestic and agricultural purposes was carried out in Chityal area, Nalgonda district of Andhra Pradesh. Groundwater is the major source for domestic and agricultural activity in the study area. 70% of the Fin groundwater samples is within the potable limit of 1.5 mg/L. Suitability of groundwater for irrigation purpose was evaluated based on US Salinity diagram, which shows that 80% of the total groundwater falls in the zone of high-salinity hazard (C3) and low-sodium hazard (S1) type. The Wilcox diagram shows that most of the groundwater (70%) falls in the category of good to permissible for irrigation purposes. The residual sodium carbonate (RSC) in groundwater is less than 1.25 meq/L and hence, suitable for irrigation. Residual sodium bicarbonate concentration varied from -1.39 to 0.86 meq/L in the study area. All the samples collected from study area are found to be satisfactory (<5 meq/L) for irrigation purposes.
Land and water are two broad components on which the entire biotic community thrive. In the study... more Land and water are two broad components on which the entire biotic community thrive. In the study area the main rock types are basalts and laterites. The main landform units in this province are-valley fills, lower plateau and upper plateau. Occurrence of groundwater in hard rock terrain is mainly controlled by structures, landforms, lithology and recharge conditions. Remote Sensing technology
Natural Resources Research, 2012
Kerala-Konkan offshore basin forms the southern part of the western continental margin of India. ... more Kerala-Konkan offshore basin forms the southern part of the western continental margin of India. The depositional models of the initial post-rift and late post-rift phases of basin evolution, suggest that Kerala-Konkan basin holds promise for hydrocarbons. The Kerala-Konkan offshore basin lying south of Mumbai offshore basin which is the major oil producing offshore basin. The structural style of Kerala-Konkan basin is similar to Bombay offshore basin. In Kerala-Konkan, the Tertiary and Mesozoic sediments are separated by a thick Basaltic layer. Imaging below basalts has always been a problem in oil exploration. The thick basalt is opaque and masks deeper seismic events below the basalt. Kerala-Konkan offshore basin is considered geologically prospective for oil and gas reserves; however, a major part of the basin is covered by the Deccan Traps, hindering the exploration of Mesozoic hydrocarbon targets. Surface geochemical prospecting, based on micro-seepage of hydrocarbons from subsurface accumulations, could be advantageous in such areas. Surface geochemical prospecting method was applied in Kerala-Konkan offshore basin for evaluation of hydrocarbon resource potential of the basin. The gas chromatographic analyses of adsorbed soil gases showed the presence of C1 to C5 hydrocarbons. The concentrations of adsorbed soil gases ranged for methane C1 = 3 to 492 ppb, ethane C2 = 4 to 326 ppb, propane C3 = 2 to 296 ppb, butane nC4 = 2 to 72 ppb, iC5 = 4 to 94 ppb, nC5 = 2 to 23 ppb and ΣC2+ (C2H6, C3H8, i-C4H10, n-C4H10, i-C5H12, n-C5H12) = 3 to 837 ppb. The scatter plots between C1 to C4 components depict linear trend indicating that all the gases are derived from the same source. The bacterial count of propane oxidizing bacteria ranged from 0.2 x 102 to 6.5 x 104 cfu/gm of soil. Two microbial blooms of high populations of the propane oxidizing bacterial were Powered by Editorial Manager® and Preprint Manager® from Aries Systems Corporation identified between (latitudes 7.6° to 8.0° N and longitudes 77.65° to 77.85° E) in the study area and appears to be more potential. Our study supports Kerala-Konkan offshore basin to be promising in terms of its hydrocarbon prospects.
Journal of Petroleum Science and Engineering, 2013
ABSTRACT The Mesozoic Kutch sedimentary basin in the western continental margin of India has know... more ABSTRACT The Mesozoic Kutch sedimentary basin in the western continental margin of India has known accumulations of oil and gas. However, the multilayered thick Deccan Traps of Late Cretaceous overlie the Mesozoic targets, thereby imposing inherent problems in imaging sedimentary layers below the traps for exploratory studies. One of the unconventional techniques, the near surface geochemical prospecting study, has been carried out in the onland and offshore Kutch to understand the microseepage and sources of the light hydrocarbon gases (methane through butane) observed in the soils and sediments from the basin. The geochemical and isotopic compositions of the soil samples from the Kutch onland vary in the range of C-1 (methane)=3-582 ppb, C-2 (ethane)=0-39 ppb, C-3 (propane)=0-15 ppb and the delta C-13(1) (methane)=-24.9 parts per thousand to -35.7 parts per thousand. The offshore sediments showed the presence of butane along with the lower hydrocarbons and the concentration ranges as C-1=36-475 ppb, C-2 = 5-27 ppb, C-3 = 5-27 ppb, iC(4)=2-6 ppb, nC(4)= 0-4 ppb, and their delta C-13 values are characterized as delta C-13(1) =-37.7%. to -44 parts per thousand, delta C-13(2)=-24.6 parts per thousand to -30.5 parts per thousand and delta C-13(3)=-26.1 parts per thousand to -34 parts per thousand. The compositional ratios and carbon isotopic signatures of light gaseous hydrocarbons suggest their thermogenic origin. The delta C-13(1)-delta C-13(2) signatures of samples from offshore Kutch indicate the gases to be non-associated, originating from sapropelic liptinitic organic matter. The concentration distribution pattern of light hydrocarbons indicates the areas Bhuj, Anjar, Mandavi and Mundra to have higher values for these gases. The anomalies are also coincident with the active faults, the Bhuj Fault (BF), the Katrol Hill Fault (KHF) and the Sandsra Dungar Fault (SDF) passing through the area, which may serve as a preferential migratory pathway for the light hydrocarbon gases. The results of this study support the generation, preservation, migration and the near surface manifestation of thermogenic hydrocarbons in Kutch basin, particularly in the northern and southern regions of the study area.
Geosciences Journal, 2012
Geomicrobial prospecting for hydrocarbons is an exploration method based on the seepage of lighte... more Geomicrobial prospecting for hydrocarbons is an exploration method based on the seepage of lighter hydrocarbons from oil/gas reservoirs to the surface and their utilization by hydrocarbon oxidizing bacteria. These bacteria utilize the hydrocarbons as their sole source of food and are found to be enriched in the near surface soils/sediments above the oil and gas reservoirs. The detection of anomalous populations of hydrocarbon utilizing bacteria in the surface soils can help to evaluate the prospects for hydrocarbon exploration. Geomicrobial prospecting studies have been carried out to test the efficacy of surface geochemical methods as regional evaluation tools in the petroliferous region of Mehsana Block, North Cambay Basin, Gujarat and to investigate whether the geomicrobial anomalies can establish an upward migration of hydrocarbons from the deep subsurface. In the present study, bacterial counts for n-pentane utilizing bacteria range between 1.0 × 10 2 and 9.80 × 10 5 cfu/g and and n-hexane utilizing bacteria range between 1.0 × 10 2 and 9.20 × 10 5 cfu/g. The bacterial concentration distribution maps show four distinct anomalies in the study area. The possibility of discovering oil or gas reservoirs using the microbiological method is emphasized by the fact that the hydrocarbon oxidizing bacteria range between 10 3 and 10 6 cfu/g in soil/sediment receiving hydrocarbon microseepages. In the present study area of the Mehsana Block of Cambay Basin, n-pentane and n-hexane utilizing bacteria show 10 5 cfu/g of soil sample, which is significant and thereby substantiates the seepage of lighter hydrocarbons from oil and gas reservoirs. Geomicrobial prospecting method has shown good correlation with existing oil/ gas fields of Mehsana, Gujarat.
Hydrogeochemical investigations carried out in parts of granitic tracts of Telangana region of In... more Hydrogeochemical investigations carried out in parts of granitic tracts of Telangana region of India revealed that the fluoride concentrations in the groundwater are much higher than the prescribed limit (>1.5mg/l). It is observed that fluorine bearing minerals like fluorite and apatite present in granitic rocks are the major source for the excessive fluoride in groundwater. Geology of the area and climatic conditions play vital role for the high concentrations of fluoride in groundwater. In addition, depletion of groundwater levels due to climatic changes is another factor for high incidence of fluorosis.
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Papers by PROF. VENKATAYOGI SUDARSHAN
optimal fluoride concentrationlevelsindrinkingwaterhavetobe
in therangeof0.5and1.5mg/Lsincethispermissiblerangeis
essential fornormalmineralizationofbonesandteethaswellas
for dentalenamelformationinhuman'sbody Bell andbudwig,
1970;AdimallaandVenkatayogi,2017;NarsimhaandSudarshan,
2013,2016;2017[1,2,4,5,6]. Ifcontinuesintakeofhigh fluoride
(41.5)watercanseverelycausedentalandskeletal fluorosis. The
investigatedareapeoplemajorlydependongroundwaterfor
drinking purposesand fluoride concentrationrangedfrom0.2to
7.4mg/Lwithmeanconcentrationof2.7mg/Landdatawas
compared withWHOguidelinesfordrinkingpurposes.Overall,
data revealsthatthe57%ofgroundwatersamplesdatawasnot
safe fordrinkingpurposes.Therefore,distributionof fluoride inthe
groundwaterofMedakregioninTelanganawassuggestedto
intake drinkingwater,whicharebelowlevelof fluoride con-
centration inthegroundwaterandtakecareabouthealthimpli-
cations.
the vulnerable areas in terms of fluoride contamination. A
total of 34 groundwater samples were collected from major
drinking water sources in rural areas of Basara, Telangana,
and studied with reference to the distribution and hydrogeochemistry
of fluoride. The geochemical trend of
groundwater in the study area demonstrates that sodium is
the dominant cation (Na?[Ca2?[Mg2?[K?) and
chloride is the dominant anion (Cl–[HCO3
–[
SO4
2–[CO3
2–[NO3
–[F–). The fluoride concentration
varied from 0.06 to 4.33 (1.13 ± 0.90) mg L-1 with the
highest fluoride level at Karegaon village (4.33 mg L-1).
Seven locations showed the presence of fluoride in excess
of permissible levels.
optimal fluoride concentrationlevelsindrinkingwaterhavetobe
in therangeof0.5and1.5mg/Lsincethispermissiblerangeis
essential fornormalmineralizationofbonesandteethaswellas
for dentalenamelformationinhuman'sbody Bell andbudwig,
1970;AdimallaandVenkatayogi,2017;NarsimhaandSudarshan,
2013,2016;2017[1,2,4,5,6]. Ifcontinuesintakeofhigh fluoride
(41.5)watercanseverelycausedentalandskeletal fluorosis. The
investigatedareapeoplemajorlydependongroundwaterfor
drinking purposesand fluoride concentrationrangedfrom0.2to
7.4mg/Lwithmeanconcentrationof2.7mg/Landdatawas
compared withWHOguidelinesfordrinkingpurposes.Overall,
data revealsthatthe57%ofgroundwatersamplesdatawasnot
safe fordrinkingpurposes.Therefore,distributionof fluoride inthe
groundwaterofMedakregioninTelanganawassuggestedto
intake drinkingwater,whicharebelowlevelof fluoride con-
centration inthegroundwaterandtakecareabouthealthimpli-
cations.
the vulnerable areas in terms of fluoride contamination. A
total of 34 groundwater samples were collected from major
drinking water sources in rural areas of Basara, Telangana,
and studied with reference to the distribution and hydrogeochemistry
of fluoride. The geochemical trend of
groundwater in the study area demonstrates that sodium is
the dominant cation (Na?[Ca2?[Mg2?[K?) and
chloride is the dominant anion (Cl–[HCO3
–[
SO4
2–[CO3
2–[NO3
–[F–). The fluoride concentration
varied from 0.06 to 4.33 (1.13 ± 0.90) mg L-1 with the
highest fluoride level at Karegaon village (4.33 mg L-1).
Seven locations showed the presence of fluoride in excess
of permissible levels.